Aplicação de sensor eletroquímico de grafeno induzido por laser para determinação da nimesulida

Abstract

Nimesulide (NMS) is a non-steroidal anti-inflammatory drug of the sulfonanilide class, with analgesic and antipyretic properties, widely used in the treatment of acute pain and inflammatory diseases, such as rheumatoid arthritis and osteoarthritis. The determination of NMS is essential for quality control in pharmaceuticals and clinical interest. Thus, the use of electrochemical methods for the quantification of NMS has advantages, such as shorter analysis time, relatively low cost and the possibility of obtaining low detection limits and high sensitivity, especially with the use of pulse techniques. In this work, a simple, fast, accurate, sensitive and low-cost electroanalytical method for the determination of NMS was developed, using laser-induced graphene electrodes (LIGe) and square-wave voltammetry (SWV). The analytical conditions such as the pH of the electrolyte and parameters of the SWV technique were optimized. After optimization, a linear working range of 11 to 131 μmol L-1

(R = 0.999), detection limit of

1.29 μmol L-1

and quantification limit of 4.29 μmol L-1 were obtained. The repeatability of the method was evaluated, resulting in a RSD of 1.90% (n = 15). The method was applied to the determination of NMS in pharmaceutical samples and in synthetic urine. For the first, a value of 101 mg/tablet of NMS was obtained. For the synthetic urine sample, three concentration levels were fortified to evaluate the accuracy of the method, obtaining recovery values of 97 to 111%. In addition, the method was selective, with a variation of less than 3% when evaluating the presence of interfering species present in the samples. Therefore, the electrochemical sensor based on LIGe presented satisfactory and promising electroanalytical performance for the quantification of NMS.